Me to.
I had an AirPort Extreme and two airport express connected over Ethernet to extend the wifi. It worked perfect and roaming were smooth between APs.
I replaced the Extreme with the Omnia. I did set up the ombia based on the AE port setting, naming etc. And all traffic to and servers on the inside works perfect.
All but the roaming between stations.
If I have been on one apples airport express 5ghz band with my MacBook Air and move away from it into some other rooms and behind some 40cm concrete walls it should roam over the omnia I would guess.
But it does not.
It still holds on to a poor 7mbit connection even though I’m standing a meter away from the omnia.
It seems as is the mac does not choose the omnia even though the ssid and password are the same. If I disable the wifi and reenable it the omnia is choosen directly.